Method for retarding abscission



Patented June 22, 1943 James F. Adams, Wilmington, Del., assignor to General Chemical Company, New York, N. Y., a

corporation of New York No Drawing. Application April 27, 1942,

. Serial No. 440,755

14 Claims.

This invention relates to improvements in retarding abscission of those parts of. growing plants which tend to become abscised at various stages during growth of the plants.

As is known, leaves, buds, flowers, fruits and vegetables often become prematurely abscised from growing plants. This phenomenon is caused by development of abscission layers or cellular structures which permit dropping prior to maturity of the plant part affected. Fruit drop prior to or during normal harvest is a source of substantial loss to growers;

The object of this invention is to provide improvements with respect to retardation or prevention of abscission of parts of growing plants. The invention aims particularly to retard growth of abscission layers in the stems of fruit such as pomes and particularly apples, citrus, nuts,

I berries, and vegetables such as pepo.

I have found that certain water-soluble alkyl phenol sulfonates, and mixtures thereof, possess properties and characteristics which retard abscission of those parts of plants which tend to become abscised at various stages during growth of the plant.

More particularly, such sulfonates are watersoluble long chain alkyl phenol sulfonates such as those containing at least 10 carbon atoms in the alkyl group. Desirably, theabscission retarding agents used are water-soluble alkyl phenol sulfonates containing 10 to carbon atoms in the alkyl group, such sulfonates preferably containing a single higher alkyl ;group.

having 10 to 30 carbon atoms. In the ordinary practice of the invention, as abscission retarding agents, I employ water-soluble alky1 phenol sulfonates containing 12 to 23 carbon atoms in the alkyl group, and more particularly, the alkyl group of such sulfonates contains 12 to 19 carbon atoms. The sulfonates are ordinarily watersoluble alkali metal salts, .e. g. alkyl phenol sodium sulfonates. The alkyl group of any particular abscission retarding agent is desirably derived from a petroleum distillate such as kerosene. These retarding agents are preferably mixtures of the indicated sulfonates, and are especially mixtures of long chain mono-alkyl derivatives 0t phenol sodium mono-sulfonate in which the long chain alkyl groups are derived from kerosene and related petroleum distillates.

- According to the preferred embodiments of the invention, the abscission retarding agents used are those of a class of materials consisting of a mixture comprising inorganic salt or salts, such 7 .less than 56 grams and not more than 168 grams about by weight of the above described water-soluble alkyl phenol sulfonates.

The abscission retarding agents of the inven tion, especially the indicated sulfonate mixtures, are obtainable by chlorinating a hydrocarbon mixture having an average carbon content of 10 to 30 carbon atoms, e. g. kerosene, condensing the chlorinated hydrocarbon mixture with a phenol, in the presence of aluminum chloride or zinc chloride, sulfonating the mixture of alkyl phenols thus produced to obtain a mixture of alkyl phenol sulfonic acids, and neutralizing alkyl phenol sulfonic acids, e. gaby sodium hydroxide, to form an aqueous solution containing inorganic sulfates in addition to alkyl phenol sulfonates. By drying such mass, after adjustment of the inorganic sulfate content if desired, there is obtained'a dry product which is a mixture of inorganic sulfate and alkyl aromatic sulfonates.

If desired the inorganic sulfates can be separated from the sulfonates in any suitable way as, for example by extracting the sulfonates with alcohol.

The sulfonate abscission retarding agents of the invention are most conveniently-applied to plant parts-to be treated in the form of simple aqueous spray solutions made up by mixing certaln limited amounts of the treating or retarding agent with water.

In practice of the invention, whether the retarding agent is used in the form of the above indicated preferred mixtures of alkyl phenol sulfonates and inorganic salt or in the form of the alkyl phenol sulfonates alone, the quantity of retarding agent employed is such that the spraysolution as ready for application to the plant contains not less than 22 grams and not more than 84, and preferably not more than about grams of the said sulfonates per gallons of aqueous spray solution. In the case of the described mixtures of alkyl phenol sulfonates and inorganic salt, the amount of mixture employed is chosen so that the spray solution contains not of such mixture. With regard to sulfonateinorganic salt mixtures of this nature, the preferred proportions are not less than 56 grams and not more than about 112 grams of mixture per 100 gallons of spray solution, experience showing that best results are obtained where the concentration of the spray solution is of the order of 84 to 112 grams of alkyl phenol sulfonate-inorganic salt mixture per 100 gallons of water.

In practice, it is advisable to include in the as alkali metal sulfates, e. g. sodium sulfate, and spray solution any suitable so-called spreading or sticking agent. For example, summer oil emulsions may be used in approximate quantities of one pint per 109 gallons of spray solution.

Other stickers or spreaders such as caseinate, or wheat or soy bean flour may be employed to advantage, these materials being ordinarily incorporated in quantity up -to about 224 grams or so per 100 gallons of spray solution. The sticker ety apple trees, drop from unsprayed trees was In another instance, the same spray solution and the resulting mixture introduced into the I water.

The abscission retarding agents of the inven-' tion are applied to the plants to be treated at a time shortly before abscission of the parts is to be expected. Particular time of application of the retarding agents is variable and dependent upon factors such as the nature. of the subject treated whether bud, leaf, fruit or vegetable;

.climatic conditions; time interval before the retarding agents become effective; and the subsequent time interval within which the retarding agents function as such. le no hard and fast rule can be stated with respect to proper time of spraying a particular plant, generally speaking, experience shows that the agents of the invention ordinarily become effective as retarding agents within about 2 to 5 days fromtime of application, and then retain their abscission retarding efilcacy ordinarily over aperiod of about to days. Hence, the retarding agents are sprayed on at a time as late as possible prior Ordinarily a single spraying with the retarding agent concentrations described adequately covers an abscission and harvest period. More than one spraying is not recommended since field work :indications are that multiple spray. applications decrease efficiency. e

The following examples show the abscission retarding properties of the treating agents of'the invention.

In all of these examples the sticking and spreading agent used in the spray solutions was a material consisting of 40% milk powder, 20% starch paste, 20% bentonite and 20% clay.

In the following two groups of tests, the abscission retarding agent used was a material composed of about 60% by weight of sodium sulfate and about 40% by weight of a mixture of alkyl phenol sulfonates containing between 12 and 19 carbon atoms in the alkyl groups, which alkyl groups were derived from kerosene.

A spray solution was made up by'adding to 100 gallons of water 112 grams of spreader and 112, grams of the above sulfonate-sodium sulfate retarding agent. The resulting solution was sprayed onto Jonathan variety apple trees 4 days 7 prior to the time abscission was expected and '1 days prior to the day counts'were made, i. e. com-. letion of harvest. The drop from unsprayed check trees was 15%, and in the case of the was used, but the McIntosh variety trees were sprayed twice; first, 5 days prior to the time abscission was expected and 20 days prior to the day counts were made, and second, 13 days prior to the day such counts were made. Fruit drop from unsprayed trees was 59%, and 37% from the sprayed trees.

For a second group of tests, a spray solution was made up by adding to 100 gallons of water 168 grams of spreader and 56 grams of the above sulfonate-sodium sulfate abscission retarding agent. Williams variety apple trees were sprayed '1 days, before abscission was expected and 11 days before harvest was completed. Unsprayed trees showed an average per cent drop of 59.5,

as compared with average per cent drop of 21.2 in the case of the sprayedtrees. In another test, in which the same spray solution was used, Jonathan variety trees were sprayed 4 days before abscission was expected and 8 days before counts were made. Drop from unsprayed check trees was 15%, and drop from the sprayed trees was.10%.

I claim:

1. The method of retarding abscission of part of a growing plant comprising treating the plant, shortly before the time abscission of the part is anticipated, with an aqueous solution containing, per 100 gallons thereof, not less than 22 and not more than 84 grams of water-soluble alkyl phenol sulfonate containing 10 to 30 carbon atoms in the alkyl group.

I 2. The method of retarding abscission of a part of a growing plant comprising treating the plant, shortly before the time abscission of the part is anticipated, with an aqueous solution containing, per 100 gallons thereof, not less than 22 and not more than 84 grams of water-soluble alkali metal salt of an alkyl phenol sulfonate "containing 12 to 23 carbon atoms in the alkyl group.

3. The method of retarding abscission of a part of a growing plant comprising treating the plant, shortly before the time abscission of the part is anticipated, with an aqueous solution containin per 100 gallons thereof, not less than 22 and not more than 84 grams of water-soluble alkyl phenol sulfonate containing 12 to 23 carbon atoms in the alkyl group, which alkyl group is derived and not more than 84 grams of water-soluble alkyl phenol sulfonate containing 12 to 23 carbon atoms in the alkyl group, which alkyl group is derived from kerosene. I

5. The method of retarding abscission of a part of a growing plant comprising treating the plant,

shortly before the time abscission of the part is fanticipated, with an aqueous solution containsprayed trees, drop was only 4.7%. In another per gallons thereof, not less than 22 and not' test, the same exceptapplied to McIntosh varimore than 45 grams of water-soluble alkyl phenol sulfonate containing -12 to 23 carbon atoms in the alkyl group.

7. The method of retarding abscission of a part of a growing plant comprising treating the plant, shortly before the time abscission of the part is anticipated, with an aqueous solution containing, per 100 gallons thereof, not less than 22 and not more than 45 grams of Water-soluble alkali metal salt of an alkyl phenol sulfonate containing 12 to 23 carbon atoms in the alkyl group, which alkyl group is derived from kerosene.

8. The method of retarding abscission of a part .znratgwwing plant comprising treating the plant,

shortly before the time abscission of the part is anticipated, with an aqueous solution containing, per 100 gallons thereof, not less than 22 and not more than 84 grams of water-soluble long chain alkyl phenol sulfonate.

9. The method of retarding abscission of apples comprising treating the fruit, shortly before the time abscission is anticipated, with an aqueous solution containing, per 100 gallons thereof, not less than 22 and not more than 84 grams of watersoluble alkyl phenol sulfonate containing 12 to 23 carbon atoms in the alkyl group.

10. The method of retarding abscission of a part of a growing plant comprising treating the plant, shortly before the time abscission of the part is anticipated, with an aqueous solution containing, per 100 gallons thereof, not less than 56 and not more than 168 grams of material comprising inorganic salt and about 40 per cent by' weight of a water-soluble alkyl phenol sulfonate containing to 30 carbon atoms in the alkyl group.

11. The method of retarding abscission of a .part of a growing plant comprising treating the plant, shortly'befo're the time abscission of the part is anticipated, with an aqueous solution containing, per gallons thereohnot less than 56 and'not more than 168 grams of material comprising inorganic salt and about 40 per cent by weight of a water-soluble alkali metal salt of an alkyl phenol sulfonate containing 12 to 19 carbon atoms'in the alkyl group, which alkyl roup is derived from a petroleum distillate.

12. The method of retarding abscission of a part of a growing plant'cemprising treating the plant, shortly before the time abscission of the part is anticipated, with an aqueous solution containing, per 100 gallons thereof, not less than 56 and .not more than 112 grams of material comprising inorganic salt and about 40 per cent by weight of a water-soluble alkyl phenol sulfonate containing 12 to 23 carbon atoms in the alkyl group.

13. The method of retarding abscission of a part of a growing plant comprising treating the plant, shortly before the time abscission of the part. is anticipated, with an aqueous solution containing, per 100 gallons thereof, not less than 56 and notmore than 168 grams of material comprising inorganic salt and about 40 per cent by weight of a water-soluble long chain alkyl phenol sulfonate.

14. The method of retarding abscission of a part of a growing plant comprising treating the plant, shortly before the time abscission of the 6 part is anticipated, with an aqueous solution containing, per 100 gallons thereof, not less than 56 and not more than 112 grams of material comprising inorganic salt and about 40 per cent by weight of a water-soluble alkali metal salt of an alkyl phenol sulfonate containing 12 to 19 carbon atoms in the alkyl group, which alkyl group is derived from kerosen JAMES F. ADAMS. 

